Well two things..
1st - Why does RDR2 hold the Meta record to you this gen when 2 Nintendo Games came out previous to it that hold the same score? If anything Zelda BOTW was the first this gen to achieve a 97 meta so that's the game to beat not RDR2 which only matched the record.
2nd - I cannot see any game this gen surpassing a 97 meta, maybe come close to matching it but not getting a 98. Too many troll reviews out there that will guarantee it wont happy. (I might be wrong) but I highly doubt it.
Apparently, BotW is a "low" 97 in the Metacritic rankings. Not sure why...probably due to possible hidden decimals that ranks the difference between the games that score a 97 or whatnot. I guess that's what the OP means when mentioning RDR2 being the highest rated game of the generation in accordance to Metacritic.
Personally, it does not really matter much to me. Regardless of how different the 97 scores are, a great game is a great game. Hell, a game that has a Metacritic score of 70-80 is worth at least looking into.
I guess if you want my answer to the OP's question, here are some games that have a chance in the future:
- The next 3D Zelda (or 2D Zelda if it goes beyond what we could expect for a 2D-2.5D type game like ALttP did years ago)
- The next 3D Mario
- Metroid Prime 4 (will be interesting as it's not being developed by Retro Studios this time around)
- Cyberpunk 2077 (I'm going by the prestige of CD Projekt Red, not sure how things will go with a new IP)
- GTA6 (if it does come out before this generation is over, though I have not heard any rumors regarding this potential game)
- Death Stranding (I guess if we're going by the reputation of Kojima as, so far, the gameplay has not intrigued me)